This invention relates to rotary power transmission systems and more particularly to power transmission systems utilizing a plurality of clutches for changing the gear ratio of a transmission. An example of such a transmission is described and explained in co-assigned U.S. patent application Ser. No. 379,549, to Vater et al, filed May 18, 1982, now U.S. Pat. No. 4,498,356, entitled "Motor Vehicle Transmission". The present invention relates to a control system for a motor clutch transmission that prevents simultaneous engagement of the HIGH and LOW gear ratio clutches and also provides for a phased disengagement of the outgoing clutch to provide for smoother shifting.